1. Field of Invention
This invention relates to float valves for controlling the level of fluid in a basin, and more particularly concerns valves for controlling the level of fluids in basins such as Christmas tree stands, aquariums, or hydroponic plant basins.
2. Description of Prior Art
The vast majority of float valves rely on a float attached at the terminal end of a rod or lever arm. In turn, the lever arm activates a separate valve mechanism. Any valve apparatus which relies on a float at the end of a lever arm has several inherent disadvantages. First, it requires substantial space for operation of the lever arm, and thus cannot be utilized in a fluid basin of atypical dimensions or of a size smaller than the lever arm member. Second, the lever arm is subject to obstruction by a foreign object in the basin, which would cause the valve to malfunction. Third, the level of fluid in the basin can be only adjusted through a trial and error method of adjusting the float on the lever arm or by bending the lever arm.
Floats have also been used in combination with pinch valves. Pinch valves are typically comprised of a flexible tube that is collapsed to control the flow of fluid. Usually, the pinch valve is activated by manual operation and not by a float. When combined with a float, however, pinch valves also have relied on the float being located at the end of a lever arm. Each of the disadvantages discussed above concerning the use of lever arms for float valves is applicable to lever arms on a pinch valve. In addition, a lever arm on a pinch valve has further disadvantages, as it is difficult to maintain the lever arm in a fixed plane because of the flexible nature of the tube comprising the pinch valve.